First thing you must do is - read the rule book, which will inform you that a deck must consists of 60 cards. But, building a deck is not just throwing together neat cards - since many of the cards have requirements that must be met in order to play them. Here are a few things to watch:

Every NetNavi has two colors that are specific to that NetNavi, except for the MegaMan NetNavi's (which you can use all four color for if you have all three expansions). So, most decks will be composed of only two colors.

Every card has a "destiny number" in the upper right corner. These are important when blasting an opponent with your NetNavi. Choose cards carefully to attain the highest possible destiny number average. Some really powerful cards often have very low destiny numbers, so you must decide which is better.

Some cards have requirements in order to play them. Requirements consists of these factors:

1. Power gauge requirement - number of bars shown on the card.
2. Color requirements for resources in play area - indicated by the small triangles shown on the center bar of the cards.
3. Icon requirements - found on cards that are specific to the NetNavi that you are using. The number of icons shown on the center bar of the card must match the icons of cards you have in your four resources allowed on the battlefield at any time.

So, you have work to do in order to complete a playable deck. You need to determine whether or not you want to use three colors (check your Battlechips). Secondly, your MiniBoomers require a NumberMan icon be on the battlefield amoung your played resources BEFORE you can play a Miniboomer card (plus the colors of those resource cards must match the small triangles in the quantities shown). Also, your one UR card (event) requires three MegaMan icons to play, and you have no cards with any MegaMan icons. It can be a really fun game to play, but building a deck is a bit more than throwing together some cards.